Rewrite as a simplified fraction. ${2.1\overline{6} = {?}}$
Explanation: Let $x$ equal the decimal. Set up two equations such that the digits after the decimal point are identical. ${\begin{align*}100x &= 216.6666...\\ 10x &= 21.6666...\end{align*}}$ Subtracting the two equations, we have: ${90x = 195}$ ${x = \dfrac{195}{90}} $ ${x = \dfrac{13}{6}} \text{or} {2 \dfrac{1}{6}}$